The Music Producers Guild (MPG) in partnership with the European Broadcast Union (EBU) have now standardized a metadata field for the International Standard Recording Code (ISRC) in wav files!  This issue has been a long time overdue, but now finally gained enough traction to make it into a standard.  The ISRC can now be embedded in wav files inside the core metadata.  This means it will follow the file where ever it goes.  We also now have software that is able to add this info to your mastered wav files, so we can offer this service to clients.

This question has come up with relative frequency, so I'm going to write the step-by-step directions to let you get your reference CD into your computer as .wav files or mp3 files.

These step by step directions are for converting a disc to .wav files, but the steps will be similar for converting to MP3 too.

Often a source of confusion is the .cda file.  On a windows computer, when you insert a RedBook Audio CD, the tracks show up as .cda files.  One might assume that these are the audio files on the disc because they are the only items that show up in the explorer window. . . that would be wrong.  The .cda files are merely placeholders pointing to a place on the CD that the song starts.  Think of them as what windows calls a 'shortcut'.
This shouldn't even be an issue, but it has become one. . . Thanks Apple. . . Since OS10.4.9, Apple has decided to change the byte order of their aiff files from big endian to little endian.  These new 'aiff' files are really AIFF-C/sowt, but all you see is 'aiff' making it hard to determine which you have.  Some programs use the old aiff format and some use the new 'aiff' format.  Due to this issue, depending on your computer, you may or may not be able to read aiff files consistently.  My advice is to abandon ship and stick to .wav files for all uses.